1. The Field of the Invention
The present invention relates generally to fiber optic communication systems. More specifically, the present invention is related to fiber optic data transfer between electronic devices in a vehicle.
2. Related Technology
Vehicles today include a variety of electronic devices that may need to communicate and interact with other electronic devices, a human user, or even outside communication systems, such as radio wave, cellular, and satellite communication systems. While this is true for almost every type of vehicle, such as airplanes, trains, boats, helicopters, motorcycles, automobiles, and other vehicles, this is particularly true for automobiles.
Automobiles today may include, for example, security systems that interact with global positioning systems (GPS), which in turn may communicate with electronic video displays and navigation systems. Automobiles may also have entertainment devices that may include, for example, compact disk (CD) players, cd-rom readers, digital video disk (DVD) players, and other analog and digital medium reading devices that may be coupled to audio amplifiers, video displays, as well as other multi-media output, imput, and interactive components. Automobiles may also include diagnostic systems, including various sensors that provide information regarding the operation and performance of the automobile. These diagnostic systems may also need to communicate with other components, such a display or control system.
The number of electronic devices in automobiles today may also create a dangerous environment by causing the driver to be distracted from operation of the automobile. Driver safety may in some instances be promoted by communication between the electrical devices in the vehicle. For example, safety may be promoted by communication between an integrated cellular phone and the entertainment devices such that when an incoming call is received, the volume of the entertainment devices is muted such that the driver may receive the cellular communication without being overly distracted from operating the automobile. In addition, a car security system may communicate with a cellular or satellite system to notify the owner, or a third party, of a theft or accident.
Some automobile manufacturers have begun to bring vehicles to market with fiber optic networks allowing certain electronic devices to interact. To communicate over a network using fiber optic technology, fiber optic components such as a fiber optic transceiver are used to send and receive optical data. Generally, a fiber optic transceiver can include one or more optical subassemblies (“OSA”) such as a transmit optical subassembly (“TOSA”) for sending optical signals, and a receive optical subassembly (“ROSA”) for receiving optical signals. More particularly, the TOSA receives an electrical data signal and converts the electrical data signal into an optical data signal for transmission onto an optical network. The ROSA receives an optical data signal from the optical network and converts the received optical data signal to an electrical data signal for further use and/or processing. Both the ROSA and the TOSA include specific optical components for performing such functions.
Most, if not all, fiber optic networks implemented in vehicles use LED-based transmitter and receiver technology optically coupled with plastic optical fiber having a diameter of about one millimeter. Using these components in a fiber optic network, however, suffers from several performance, and reliability problems. For example, these networks are typically only operable in the temperature range of negative 40 degrees Celsius to positive 85 degrees Celsius. It may be desirable, however, to place components of the network in the roof of the automobile or near the engine, where more extreme temperatures are common. In this case, the networks used today may exhibit communication transmission problems or even failure.
In addition, plastic optical fiber of 1 millimeter thickness suffers from the limitation that it has a relatively large functional bending radius (rmin=5 cm). Plastic optical fiber's larger bending radius can create problems in automobiles where the space allowed for running the plastic optical fiber may be limited without substantially altering the design of the automobile.
Plastic optical fiber also suffers from the limitation that it is easily damaged or deformed. For example, plastic optical fiber may be damaged by various forces placed on the fiber during automobile production. This damage may result in light transmission failure or increased light attenuation.
Plastic optical fiber of 1 millimeter thickness and LEDs are also limited in their ability to transfer large amounts of data across relatively long distances of cable using highly modulated light. More specifically, using 1 millimeter plastic fiber and LEDs for transmission can limit the transmission to only certain spectrums, to a distance of transmission of about 50 meters, and limits the rate of data transfer to about 50 Mbit/s.
Therefore, it would be advantageous to implement a fiber optic network in a communication system between electronic devices used in a vehicle that is less susceptible to potentially damaging environmental and production conditions, and allows for higher transmission rates of data among the various electronic devices in a vehicle.